Hirshhorn Museum and Sculpture Garden. Photo: Courtesy of the Smithsonian.

By: Brett Zongker, Associated Press

WASHINGTON (AP).- More than 1,600 museums across the country will offer free admission to active-duty military personnel and their families this summer in a program that has more than doubled in size since 2010.

The expanded Blue Star Museums initiative was announced Tuesday at the Metropolitan Museum of Art in New York City where more than 40 museums are participating. The offer of free admission runs from Memorial Day until Labor Day at sites nationwide.

The program began in 2010 as a partnership between the National Endowment for the Arts, Blue Star Families and the Defense Department. It's adding 300 new museums this year.

New participants include the American Civil War Center at Historic Tredegar in Richmond, Va., the New Mexico Museum of Space History, San Francisco's Children's Creativity Museum and the World Figure Skating Museum and Hall of Fame in Colorado Springs, Colo.

First lady Michelle Obama and Jill Biden, wife of Vice President Joe Biden, also are helping to promote the effort this year through their Joining Forces initiative to support military families. It comes at an important time for military families and can be a way to welcome military families to new communities as they often relocate, said Navy Capt. Brad Cooper, executive director of Joining Forces.

"A large percentage of moves happen over the course of the summer," often from one end of the country to the other, Cooper said. Opening access to museums "really just opens up the aperture of what families are able to do in their travels and their vacation time," he said.

Rocco Landesman, chairman of the National Endowment for the Arts, said it's good for museums, too.

"This is both an opportunity to thank military families for their service and sacrifice, as well as a chance to create connections between museums and these families that will continue throughout the year," he said in a statement.

Last week, the Interior Department announced it would give military families free access to every national park in the country with annual passes. The passes normally cost $80 and provide access to more than 2,000 national parks, wildlife refuges and other public lands.

Obama and Biden also are focused on expanding job opportunities for military spouses and improving military health services and education for military children.